>Now here is a question. >How long does it take for your D7k to shut off?
If you're pressing the shutter button to take a photo and then immediately turning off the camera, then the camera won't shut off until the photo you took has been fully saved to the SD card. If the SD card is a basic class 10 card (10-20/MBs) or slower, it could take anywhere from 4-12 seconds for a large, fine JPG+NEF file to save and then allow the camera to shut off.
I hope this isn't off-topic, but normally when I occasionally shut off my D7K it has usually already been idle for 30 seconds of more. No shots being saved, the meter has already idled automatically, the camera systems are in idle mode (typical of most DSLR cameras by all makers), etc. The camera shut off is instantaneous.
There is an idling subsystem in all Nikon DSLR bodies which provides minimal power for clock timing (a pickup from the internal lithium button battery), top LCD readout of remaining main battery capacity or remaining shots or both, and some other very low-drain systems to remain active when the camera is shut off and the main battery is installed. Nikon DSLR bodies can remain shut off, with no appreciable drain on the main battery, for at least four months (depending on the age and condition of the main battery). My point is that if you're actively concerned about best shooting practices with respect to conserving battery life while shooting, and/or generally best practices with respect to getting the longest overall life out of the battery, there is very little to be concerned about.
I turn my camera on at the beginning of a city walkabout, trip (including plane travel, car travel, boat travel - thousands of miles/kilometers), hike, work day, etc., etc., and don't turn it off unless I have have to change cards, change lenses, clean the sensor filter or mirror box, or change the battery. Leaving the camera on simply results in it going idle, as designed, until I half-press the shutter button to wake it up. I know that there has to be a difference in battery life between charges when leaving it on as I've described, but it's a small enough difference for my purposes to be completely irrelevant.